Patent GB-425261-A (GB)
Title: Improvements in or relating to vulcanising presses
IPC: B29D30/06
Filed: 1934-02-20
Abstract: 425,261. Vulcanizing tyres. SOC. ITALIANA PIRELLI, and COZZO, G., 21, Via Fabio Filzi, Milan, Italy. Feb. 20, 1934, Nos. 5627 and 5628. Convention dates, Feb. 20, 1933 and March 25, 1933. [Class 70] In a " watch-case " vulcanizer for tyres and inner tubes, of the type comprising means for clamping the press halves together and power means for effecting the relative movement of the halves and for actuating the clamping means, the power means comprises a piston-and-cylinder device common to the clamping means and press halves and rockably mounted, the piston one one of these elements and the cylinder on the other, or on parts respectively movable therewith, and the clamping means comprises two opposed coacting hook members connected one to one press half and the other to the other press half and arranged during the closing of the press first to move into operative alignment with one another and then to enter into operative engagement so as to clamp the halves together, the inverse movement being performed during the opening of the press. As shown in Fig. 1 the cylinder 11 is mounted on the tail of a press half 1 rockable about a pivot 4, and the piston 15 is pivotally connected at A to one of a pair of triangular links 18 pivotally mounted at a fixed point 19 in the frame below the fixed press half 2. One hook member 16 is pivoted at 17 to the press half 1 and the other hook member consists of two jaws 24, 25, pivotally mounted on a common pin 21 suspended by means of two links 20 on two pins 22 each passing through an apex of one of the links 18. These linkages constitute a toggle joint. The pin 21 is pivotally connected by links 23 to fixed pivots B in the framework. The press halves are shown clamped together, hook ends 27, 28, on the jaws 24, 25, respectively being in operative engagement with hook ends 29, 30, on the member 16. To open the press, pressure is relieved from the righthand end of the cylinder and admitted to the left-hand end. The piston 15 thereupon retracts towards the right, the cylinder 11 remaining practically stationary during the first part of this retraction. The links 18 are thereby swung around 19, the pins 22 move to the right and the toggle is broken, pin 21 rising on the ends of links 23. Jaws 24, 25, therefore rise, relieving clamping pressure on the press halves, until the upper extremity of the jaw 25 abuts a stop 32 on the member 16 and pushes the half 1 upwards, thereby opening the press. This upward movement of the jaws continues until a stop 34 on the jaw 24 abuts a stop 35 coaxial with a pivot B, when angular separation of the jaws takes place against a compression spring 26. By now, owing to the angular movement of the member 16 as the press half 1 swings about 4 the hook end 30 of the said member is clear of the hook 28, and by the time a stop 36 on the jaw 24 abuts a stop 37 on the frame, angular separation thus ceasing, hook 27 has moved clear of hook 29. The full weight of the half 1 is now taken by the cylinder 11 which moves towards the left, the piston 15 being now stationary. In the closing of the press the reverse movements occur the jaws closing into operative alignment, the jaw 25 taking part of the weight of the half 2, and the jaws moving in the direction of their lengths into operative engagement. In two modified machines for vulcanizing two articles simultaneously, having a doublesided mould-half positioned between two halves, the upper, movable half and the doublesided half being linked by a lost motion device, the cylinder is mounted on the tail of the upper half, as shown, or on a link similar to 18, the piston being connected to the upper half. In these two constructions there is very little play between the hook members 27, 28, 29, 30. A strut may be hinged to the frame, for the purpose of propping open the doublesided half and the upper half.